Apparatus for producing an integrally laminated three-dimensional object by repeating formation of powder layer and solidified layer

ABSTRACT

An apparatus for producing a laminated object, includes a powder layer forming unit for forming a powder layer of a powdery material, a material supply unit for feeding the powdery material to the powder layer forming unit; and a solidified layer forming unit for forming a solidified layer by irradiating a light beam on a specified portion of the powder layer and sintering or melting the specified portion of the powder layer. The apparatus is configured to produce an integrally laminated three-dimensional object by repeating formation of the powder layer and formation of the solidified layer. The material supply unit includes a cartridge unit charged with the powdery material, the cartridge unit being configured to allow the powdery material to drop downwards.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/461,176, filed Aug. 4, 2009, which claimsbenefit to Japanese Application No. 2008-202050, filed Aug. 5, 2008, theentire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an apparatus for producing athree-dimensional laminated object by irradiating a light beam on aspecified portion of a powdery material and curing the specified portionlayer-by-layer.

BACKGROUND OF THE INVENTION

Conventionally, there is known an apparatus for producing athree-dimensional laminated object, wherein a powder layer of aninorganic or organic powdery material is formed on a base, a light beamis irradiated on a specified portion of the powder layer to sinter andcure the powdery material in the specified portion to thereby form asolidified layer and the preceding steps are repeated while moving thebase up and down so that the solidified layers are laminated into asingle body (see, e.g., Japanese Patent Laid-open Publication No.2002-115004).

FIGS. 9A and 9B partially illustrate the configuration of a conventionalapparatus for producing a laminated object. The laminated objectproduction apparatus includes a shaping unit 104 in which to form apowder layer and a solidified layer and a material supply unit 105 fromwhich to supply a powdery material to the shaping unit 104. The shapingunit 104 includes a shaping table 140, an elevator 142 for moving theshaping table 140 upwards and downwards and a shaping frame 141 arrangedto surround the shaping table 140. The material supply unit 105 includesa storage tank 151 for storing a powdery material, a lifting mechanism152 and a lifting table 150 for pushing up the powdery material storedwithin the storage tank 151, and a material supply blade 120 fortransferring an upper layer portion of the powdery material storedwithin the storage tank 151 onto the shaping table 140 and for levelingthe surface of the powdery material transferred to the shaping table140.

With this apparatus, a solidified layer is formed by sintering aspecified portion of a powder layer on the shaping table 140 through theuse of a solidified layer forming unit (not shown) that irradiates alight beam. Then, the shaping table 140 is moved downwards to form anext powder layer. Formation of the powder layer is performed by movingthe lifting table 150 upwards by a short distance, bringing the upperlayer of the powdery material stored in the storage tank 151 into aposition a little higher than the upper surface of the shaping frame141, and transferring the powdery material on the lifting table 150 tothe shaping table 140 by the sliding movement of the material supplyblade 120.

In the apparatus referred to above, it is sometimes the case that theheight h2 of the material supply unit 105 becomes twice or more greaterthan the height h1 of the storage tank h1 in order to allow the liftingtable 150 to make up-and-down movement. Such a structure of the materialsupply unit 105 results in an increase in the size of the apparatus. Inaddition, the powdery material stored in the storage tank 151 is placedin an open space and is, therefore, apt to be degraded by oxidization ormoisture absorption. For that reason, the sintering and curing performedby the light beam becomes uneven, which may possibly reduce theprecision and accuracy of the produced object. Moreover, if the powderymaterial is used up during a forming process and if it becomes necessaryto feed the powdery material into the storage tank 151, there is nochoice but to stop the apparatus. This leads to reduction in the workefficiency. Additionally, the powdery material is partly splashed in thefeeding process thereof, thus making the apparatus dirty. It isimpossible to carry out the material feeding operation in an easy andconvenient manner.

SUMMARY OF THE INVENTION

In view of the above, the present invention provides an apparatus forproducing a laminated object, which is small in size, capable ofrendering a powdery material less susceptible to degradation caused byoxidization or moisture absorption and also capable of making it easy tofeed the powdery material.

In accordance with an aspect of the present invention, there is providedan apparatus for producing a laminated object, including: a powder layerforming unit for forming a powder layer of a powdery material; amaterial supply unit for feeding the powdery material to the powderlayer forming unit; and a solidified layer forming unit for forming asolidified layer by irradiating a light beam on a specified portion ofthe powder layer and sintering or melting the specified portion of thepowder layer, the apparatus being configured to produce an integrallylaminated three-dimensional object by repeating formation of the powderlayer and formation of the solidified layer, wherein the material supplyunit comprises a cartridge unit charged with the powdery material, thecartridge unit being configured to allow the powdery material to dropdownwards.

With such configuration, the powdery material can be fed from thecartridge unit, which makes it possible to provide a low-profile compactapparatus for producing a laminated object. Since the powdery materialis charged in the cartridge unit, it is possible to render the powderymaterial less susceptible to degradation caused by oxidization ormoisture absorption. All that needs to be done in feeding the powderymaterial is to merely install the cartridge unit in a specifiedposition. This makes it possible to feed the powdery material in an easyand convenient manner.

The apparatus may further include a transportation unit for clamping andtransporting the cartridge unit.

With such configuration, even if the forming operation is underway, thecartridge unit can be transported by operating the transportation unit.This makes it possible to feed the powdery material in a timely manner.

The powder layer forming unit may include a powdery material storageunit, the material supply unit being configured to feed the powderymaterial charged in the cartridge unit to the powdery material storageunit.

Preferably, the powdery material storage unit is configured to allow thecartridge unit to be partially or fully inserted thereinto.

With such configuration, the powdery material is fed to a limited area,i.e., the powdery material storage unit. This prevents the powderymaterial from scattering over the forming unit or other parts, thusmaking it possible to feed the powdery material in an efficient manner.

Alternatively, the material supply unit may be configured to feed thepowdery material charged in the cartridge unit onto a base on which thepower layer and/or the solidified layer is formed or a base framesurrounding the base.

The cartridge unit may include a plurality of cartridge unitsconnectable to one another.

With such configuration, the quantity of the powdery material fed at onetime can be adjusted by changing the number of the cartridge unitsconnected to one another.

The cartridge unit may be formed to have a downwardly tapering shape.

The cartridge unit may have an inner surface and a spiral groove or aspiral protrusion formed on the inner surface thereof.

With such configurations, the cartridge unit is shaped and arranged toprevent the powdery material from staying behind within the cartridgeunit, which makes it possible to efficiently feed the powdery material.

The cartridge unit may have a bottom portion and a mouth formed in thebottom portion, the powdery material charged in the cartridge unit beingdropped through the mouth.

The powder layer forming unit may include a needle portion for piercingthe bottom portion of the cartridge unit.

With such configurations, it is possible to feed the powdery materialfrom the cartridge unit to the powdery material storage unit with asimplified configuration.

The cartridge unit may have a powder dispensing mouth through which tofeed the powdery material, the powder dispensing mouth being openableand closable.

With such configuration, the powder dispensing mouth of the cartridgeunit can be selectively opened and closed. This makes it possible toadjust the feeding quantity of the powdery material in a timely manner.

The cartridge unit may have a powder dispensing mouth through which tofeed the powdery material, the powder dispensing mouth being openableand closable, and the cartridge unit may be configured to allow thepowder dispensing mouth to be opened when the cartridge unit is insertedinto the powdery material storage unit.

With such configuration, the powder dispensing mouth of the cartridgeunit can be opened when the cartridge unit is fitted to the powderymaterial storage unit. This makes it possible to reliably supply thepowdery material.

The cartridge unit may be configured to allow the mouth to be opened insynchronism with movement of the powder layer forming unit.

With such configuration, the powder dispensing mouth of the cartridgeunit is opened only when there exists a need to feed the powderymaterial. This makes it possible to feed the powdery material in aproper quantity and to suppress degradation of the powdery material.

The cartridge unit may have a screw installed therein.

With such configuration, the screw is rotated within the cartridge unitto stir the powdery material, which makes it possible to prevent thecartridge unit from clogging with the powdery material and to smoothlyfeed the powdery material. Even when the powder dispensing mouth of thecartridge unit is closed, it is possible to stir the powdery materialcharged in the cartridge unit. This makes it possible to keep uniformthe particle size and homogeneity of powdery material components.

The apparatus may further include a drying unit for drying the powderymaterial charged in the cartridge unit.

With such configuration, the powdery material contained in the cartridgeunit is subjected to heating, which makes it possible to prevent thepowdery material from absorbing moisture.

The apparatus may further include a vibration unit for vibrating thecartridge unit.

With such configuration, there is no possibility that the powderymaterial stays behind within the cartridge unit. This ensures that thepowdery material is completely used up with no waste.

The cartridge unit may have an internal space charged with the powderymaterial and kept hermetically sealed.

With such configuration, the powdery material is hardly degraded byoxidization or moisture absorption even when the cartridge unit is notin use. This makes it possible to preserve the cartridge unit for anextended period of time.

The cartridge unit may be made of a reusable plastic material or a papermaterial with sealability.

With such configuration, the cartridge unit is disposable, whichenhances the convenience in using the cartridge unit.

The cartridge unit may include a memory for storing components of thepowdery material charged in the cartridge unit.

With such configuration, the status of the powdery material charged inthe cartridge unit can be recognized by reading the data of the memory.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view showing an apparatus for producing alaminated object in accordance with a first embodiment of the presentinvention, and FIG. 1B is a partial side section view thereof.

FIG. 2A is a perspective view showing a cartridge unit employed in theapparatus of the first embodiment, and FIG. 2B is a partiallysee-through perspective view thereof.

FIG. 3 is a perspective view for explaining a material supply methodused in the apparatus of the first embodiment.

FIGS. 4A through 4F are partial side section views illustrating theoperation examples of the apparatus of the first embodiment.

FIGS. 5A through 5F are partial side section views illustrating theoperation examples of the apparatus of the first embodiment.

FIGS. 6A through 6C are perspective views for explaining the materialsupply sequence in an apparatus for producing a laminated object inaccordance with a second embodiment of the present invention.

FIG. 7 is a partially see-through perspective view showing a cartridgeunit used as a modified example in the apparatus of the secondembodiment.

FIG. 8 is a schematic section view showing an apparatus for producing alaminated object in accordance with a modified embodiment of the presentinvention, in which the powdery material charged in a cartridge unit isnot supplied to a material storage frame but to a base frame surroundinga base.

FIG. 9A is a partially cut-away perspective view showing a conventionalapparatus for producing a laminated object, and FIG. 9B is a sidesection view showing a material supply unit thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An apparatus for producing a laminated object in accordance with a firstembodiment of the present invention will now be described in detail withreference to FIGS. 1A and 1B.

The apparatus 1 of the present embodiment includes a powder layerforming unit 2 for forming a powder layer of an inorganic or organicpowdery material M, an optical device 3 (or a solidified layer formingunit) for forming a solidified layer by sintering or melting a specifiedportion of the powder layer with a light beam, a shaping unit 4 having abase 40 on which the powder layer and the solidified layer are formedand a base frame 41 surrounding the outer circumference of the base 40,a cartridge unit 5 (or a material supply unit) for supplying the powderymaterial M to the powder layer forming unit 2, and a cutting unit 6 (ora transportation unit) for cutting the surface of an integrallylaminated three-dimensional object and for transporting the cartridgeunit 5. The cartridge unit 5 is charged with the powdery material M andis detachably attached to a suitable position of the powder layerforming unit 2.

The powder layer forming unit 2 includes a slide member 20 arranged forsliding movement along the upper surface of the base frame 41, ahorizontal rail 21 arranged in parallel to the upper surface of the baseframe 41 and a slide drive unit 22 for causing the slide member 20 toslide along the horizontal rail 21. The lower surface of the slidemember 20 makes contact with the upper surface of the base frame 41. Theslide member 20 moves along the horizontal rail 21 by the driving forceof the slide drive unit 22 to bring the powdery material M onto the base40.

The slide member 20 includes a slide frame 23 having a lower surfaceopening whose area is greater than that of the upper surface of the base40 and a material storage frame 24 (or a powdery material storage unit)installed adjacent to the slide frame 23 for storing the powderymaterial M fed from the cartridge unit 5. Preferably, the materialstorage frame 24 is configured so that all or a part of the cartridgeunit 5 can be inserted into the material storage frame 24.

The optical device 3 includes a light source 31 with a laser oscillator,a scanning mechanism 32 having a collecting lens and a galvanometermirror for deflecting the irradiation direction of a light beam, and anoptical fiber 33 for interconnecting the light source 31 and thescanning mechanism 32. If the powdery material M contains iron, a CO₂laser or an Nd-YAG laser is used as the light source 31.

The shaping unit 4 includes a table 42 for holding the base 40 and anelevator 43 for moving the base frame 41 upwards and downwards, inaddition to the base 40 and the base frame 41 set forth above. The base40 is fixed to the table 42. A space surrounded by the inner surface ofthe base frame 41, namely a specified space into which the powderymaterial M is fed, is created above the base 40 as the base frame 41 ismoved upwards by the elevator 43.

The cartridge unit 5 includes a housing 50 in which the powdery materialM can be charged. In the bottom portion of the cartridge unit 5, thereis formed a dispensing mouth 51 through which the powdery material M canbe fed to the material storage frame 24. The cartridge unit 5 has, e.g.,grooves or protrusions (not shown) formed on its outer surface so that aclamp unit 7 for interconnecting the cartridge unit 5 and the cuttingunit 6 can be removably attached to the cartridge unit 5 with ease. Thedetailed configuration of the cartridge unit 5 will be described later.The clamp unit 7 has, e.g., a hook member for gripping or holding thecartridge unit 5. The clamp unit 7 is configured to clamp the cartridgeunit 5 and unclamp the same in a specified position and at apredetermined timing. In addition, the clamp unit 7 has a connectorportion by which the clamp unit 7 can be connected to the cutting unit6.

The cutting unit 6 includes a headstock 61 that can be subjected to atleast three-axis control with respect to the table 42, a processingmachine 62 mounted to the headstock 61 and a spindle head 63 for holdingan end mill used in cutting the surface of a three-dimensional objectformed of integrally laminated solidified layers. The headstock 61 isconfigured to be driven in the X-, Y- and Z-axis directions asillustrated in FIG. 1A. Preferably, the headstock 61 may include amechanism capable of automatically changing an end mill. As shown inFIGS. 1A and 1B, the optical device 3 is preferably configured so thatit can be removably attached to the side surface of the processingmachine 62.

The spindle head 63 is configured to engage and disengage with the clampunit 7. By operating the headstock 61, the processing machine 62 and thespindle head 63, the cutting unit 6 can transport the cartridge unit 5held by the clamp unit 7 to a specified position of the powder layerforming unit 2, e.g., onto the material storage frame 24 as shown inFIGS. 1A and 1B. Alternatively, the cartridge unit 5 may be detachablyattached to the clamp unit 7 through the use of a magnetic force byproviding a magnetic body in a specified position of the cartridge unit5 and providing an electromagnet in the clamp unit 7. Although thecutting unit 6 also serves to transport the cartridge unit 5 in thepresent embodiment, a transportation unit dedicated to thetransportation of the cartridge unit 5 may be provided independently ofthe cutting unit 6.

The detailed configuration of the cartridge unit 5 will now be describedwith reference to FIGS. 2A and 2B. The cartridge unit 5 includes aconnector mechanism 52 for connecting one cartridge unit to another. Theconnector mechanism 52 includes, e.g., a protrusion 52 a and a groove 52b. If one cartridge unit is vertically slid relative to another, theprotrusion 52 a of one cartridge unit engages with the groove 52 b ofanother cartridge unit. As an alternative example, a plurality ofcartridge units 5 may be connected to one another through the use of amagnet. With this configuration, the quantity of the powdery material Mfed at one time can be adjusted by changing the number of the cartridgeunits 5 connected. If the dispensing mouth 51 is made openable andclosable, the powdery material M can be selectively fed to a specifiedposition of the material storage frame 24. This makes it possible toavoid excessive supply of the powdery material M.

Preferably, the cartridge unit 5 is formed into such a shape as to allowthe powdery material M charged in the cartridge unit 5 to fall withease. More specifically, the cartridge unit 5 is formed to have adownwardly tapering shape. A spiral groove or protrusion 53 ispreferably formed on the inner surface of the cartridge unit 5. Thisensures that the powdery material M can be efficiently fed to thematerial storage frame 24 with no powdery material remaining within thecartridge unit 5.

The cartridge unit 5 is configured so that the internal space thereofcan be hermetically sealed when the powdery material M is not fed. Thisensures that the powdery material M is hardly degraded by oxidization ormoisture absorption. More specifically, the housing 50 of the cartridgeunit 5 defines a space fully closed except for the dispensing mouth 51which is also closed when the powdery material M is not fed. An inertgas, e.g., nitrogen gas or argon gas, is filled in the housing 50. Bydoing so, the powdery material M is hardly degraded by oxidization ormoisture absorption even when the cartridge unit 5 is not in use. Thismakes it possible to preserve the cartridge unit 5 for an extendedperiod of time. It is preferred that the housing 50 of the cartridgeunit 5 is made of, e.g., reusable plastic or paper with sealability.This allows a user to dispose the cartridge unit 5 after its use, whichenhances the convenience in using the cartridge unit 5.

Next, a method of feeding the powdery material M from the cartridge unit5 to the material storage frame 24 will be described with reference toFIG. 3. The dispensing mouth 51 formed in the bottom portion of thecartridge unit 5 is closed by a sealing material made of paper oraluminum foil. The material storage frame 24 of the powder layer formingunit 2 is provided with a needle portion 25 for piercing the bottomportion of the cartridge unit 5. If the cartridge unit 5 is transportedonto the material storage frame 24 and if the dispensing mouth 51 ispushed into the material storage frame 24, the sealing member is piercedby the needle portion 25. As a result, the powdery material M charged inthe cartridge unit 5 is dropped into the material storage frame 24. Thismakes it possible to feed the powdery material M from the cartridge unit5 to the material storage frame 24 with a simplified configuration.

The cartridge unit 5 may be provided with a memory (not shown) forstoring such data as the components of the powdery material M chargedtherein, the charging date of the powdery material M and the quantity ofthe powdery material M. This allows a user to recognize the status ofthe powdery material M charged in the cartridge unit 5 by reading thedata of the memory with a data reading device (not shown). Preferably,the apparatus 1 includes a reading and writing device for reading andwriting the data from and into the memory and a display unit (not shown)for displaying the data. The reading and writing device referred toherein performs the data reading operation or other operations in acontact or non-contact manner through the clamp unit 7 or the materialstorage frame 24. This allows a user to recognize, during a formingoperation, the status of the powdery material M charged in the cartridgeunit 5.

The detailed configuration of the slide member 20 will now be describedwith reference to FIG. 3. When a light beam is irradiated on a powderlayer to sinter the same, it is sometimes the case that the powder layermakes contact with the ambient air and gets oxidized depending on thekind of the powdery material M used, which results in an undesiredsintering. In view of this, the slide frame 23 having a window 26 isarranged on the base 40 in the sintering process. The light beam isirradiated in the state that an inert atmospheric gas is filled in thespace surrounded by the base 40, the slide frame 23 and the window 26.This makes it possible to prevent the powder layer from making contactwith the ambient air and, consequently, to avoid defective sinteringwhich would otherwise occur by the oxidization of the powdery materialM. Quartz glass is used as the window 26 if the light beam is a YAGlaser beam, and zinc selenide or the like is used as the window 26 ifthe light beam is a CO₂ laser beam. The window 26 may be configured toserve as, e.g., an fθ lens, and not a simple parallel plate. Thisensures that the spot of the light beam on the sintering surface has auniform diameter, which makes it possible to perform the sintering withincreased density.

Next, the operation examples of the apparatus 1 of the presentembodiment will be described with reference to FIGS. 4A through 4F andFIGS. 5A through 5F. When the forming process is started, the elevator43 keeps the base frame 41 moved up from the table 42 by a distance. Thecartridge unit 5 is equipped with the clamp unit 7 and arranged abovethe base frame 41. The initial position of the cartridge unit 5 is notlimited to the top of the base frame 41. Installation of the cartridgeunit 5 in the initial position may be performed by a user orautomatically performed by the cutting unit 6 or a dedicatedtransportation mechanism (not shown). In order to feed the powderymaterial M, the processing machine 62 is moved above the clamp unit 7.The spindle head 63 is extended and connected to the clamp unit 7 (seeFIG. 4A).

The processing machine 62 lifts up the cartridge unit 5 through thespindle head 63 and the clamp unit 7 and moves along the headstock 61(see FIG. 4B), thus transporting the cartridge unit 5 to above thematerial storage frame 24 (see FIG. 4C). If the cartridge unit 5 istransported by the processing machine 62 in this manner, it becomespossible to feed the powdery material M in a timely manner withoutstopping the apparatus during the forming process.

Then, the processing machine 62 extends the spindle head 63 to bring thedispensing mouth 51 of the cartridge unit 5 into the material storageframe 24. As a result, the sealing material hermetically sealing up thedispensing mouth 51 is pierced by the needle portion 25 provided in thematerial storage frame 24, allowing the powdery material M charged inthe cartridge unit 5 to drop into the material storage frame 24 (seeFIG. 4D). Thus the powdery material M is fed to the limited areasurrounded by the material storage frame 24 and is prevented fromscattering over the upper surface of the base frame 41. The powderymaterial M can be efficiently fed to above the base 40 by causing thesliding movement of the slide member 20.

Thereafter, the clamp unit 7 is unclamped from the cartridge unit 5 andtransported to a specified position (FIG. 4E). As the slide member 20 isslid along the horizontal rail 21, the powdery material M in thematerial storage frame 24 is supplied onto the base 40. At this time,the surface of the powdery material M is leveled to thereby form a firstpowder layer S1 (see FIG. 4F).

Subsequently, the optical device 3 irradiates a light beam L on aspecified area of the powder layer S1 to sinter the powder in that area,thereby forming a first solidified layer H1 (FIG. 5A). The irradiationroute (or hatching route) of the light beam L is preset from thethree-dimensional CAD data of a laminated object. In other words, theirradiation route of the light beam L is set for each and every layerusing the contour data of the respective cross-sections obtained byslicing, at an equal pitch, the STL (Standard Triangulation Language)data originating from a three-dimensional CAD model. At this time, thesintering is performed so that at least the outermost surface of alaminated object has high density (with the porosity of 5% or less) butthe inner portion thereof shows low density. In other words, the shapemodel data are preliminarily divided into surface layer data and innerportion data. Then the light beam L is irradiated in such a sinteringcondition that the inner portion becomes porous while the surface layeris nearly melted to have high density. This makes it possible to obtaina three-dimensional object having a dense surface.

After the sintering is performed, the elevator 43 pushes the base frame41 up to a specified height (see FIG. 5B). The powdery material M is fedon the base 40 again to form a second powder layer S2 (see FIG. 5C). Theheight by which the base frame 41 is pushed up is set equal to thethickness of the second powder layer S2 laminated on the first powderlayer S1 and the first solidified layer H1. The thickness of each of thepowder layers S is set equal to about 0.05 mm in case of producing alaminated object, e.g., a shaping mold. The three-dimensional object inwhich a plurality of solidified layers H is integrally laminated oneabove another can be formed by repeating the formation of the powderlayers S and the formation of the solidified layers H (see FIG. 5D). Asset forth above, if the base frame 41 is moved up it becomes possible tolaminate the solidified layers H without having to move the base 40.This makes it possible to produce three-dimensional objects with highaccuracy. The present invention is not limited to the afore-mentionedconfiguration in which the base frame 41 is moved upwards while keepingthe base 40 fixed. As an alternative example, it may be possible toemploy a configuration in which the base is moved downwards whilekeeping the base frame fixed (see FIGS. 9A and 9B).

The steps shown in FIGS. 5A through 5D are repeatedly performed untilthe overall thickness of the solidified layers H thus laminated becomesequal to a value calculated from the length of the end mill 64 attachedto the spindle head 63 of the processing machine 62. Then, theprocessing machine 62 is moved to above the base 40 and the surface ofthe integrally laminated three-dimensional object is cut with the endmill 64 (FIGS. 5E and 5F). Examples of the end mill 64 used hereininclude a two-blade type ball end mill made of cemented carbide.Depending on the shape to be cut or the purpose, it may be possible touse a square end mill, a radius end mill, a drill or the like. Just likethe irradiation route of the light beam L, the cutting route tracked bythe processing machine 62 is preset from the three-dimensional CAD data.The excess cured portion of powder attached to the surface of thethree-dimensional object is removed by the cutting operation mentionedabove, ensuring that the high-density portion is exposed on the surfaceof the three-dimensional object. After the cutting operation isperformed by the processing machine 62, additional powder layers S andadditional solidified layers S are repeatedly formed, eventuallyproducing a desired three-dimensional object.

Preferably, the apparatus 1 of the present embodiment includes a dustremoval unit (not shown) having an air pump, a suction nozzle and thelike. Prior to the cutting operation performed by the processing machine62, the dust removal unit removes the non-sintered excess powder for thesake of enhanced cutting accuracy. After the cutting operation, thechips generated in the cutting process are removed by the dust removalunit. More preferably, the dust removal unit includes a plurality ofnozzles corresponding to the objects to be removed, i.e., the excesspowder and the chips, which makes it possible to separately collect theexcess powder and the chips.

With the configuration described above, the powdery material M can befed by use of the cartridge unit 5. This makes it possible to reduce theheight of the apparatus and to provide the apparatus which is morecompact than the conventional one. The powdery material M is charged inthe cartridge unit 5 and, therefore, is hardly degraded by oxidizationor moisture adsorption. It is also possible to keep the apparatus frombeing contaminated by the powder during the material feeding process. Inaddition, the user can install the cartridge unit 5 in a specifiedposition without having to touch the powdery material M, which makes itpossible to feed the powdery material M in an easy and convenientmanner.

Next, an apparatus for producing a laminated object in accordance with asecond embodiment of the present invention will be described withreference to FIGS. 6A through 6C. The apparatus 1 of the presentembodiment differs from that of the first embodiment in theconfiguration of a cartridge unit 5′ and a material storage frame 24′.In the present embodiment, a drum-shaped housing 50′ is employed in thecartridge unit 5′. The housing 50 may be configured so that it can bepartially or fully inserted into the material storage frame 24′. Thecartridge unit 5′ is provided in its bottom portion with a powderdispensing mouth 54 through which to feed the powdery material M to thematerial storage frame 24′. Lid plates 55 for opening and closing thepowder dispensing mouth 54 are installed to slide along the powderdispensing mouth 54 and the side surface of the housing 50′. As in thefirst embodiment, the cartridge unit 5′ of the present embodiment istransported by the cutting unit 6 and the clamp unit 7 having a shapeconforming to that of the housing 50′ (although not shown in FIGS. 6Athrough 6C).

The lid plates 55 are provided with lid levers 56 extending in thelongitudinal direction of the cartridge unit 5′, while the materialstorage frame 24′ is provided with upwardly-protruding bars 27positioned in alignment with the lid levers 56. The lid plates 55 arebiased by springs or the like so as to close the powder dispensing mouth54. Therefore, the powder dispensing mouth 54 is kept closed when thelid levers 56 and the bars 27 of the material storage frame 24′ remainspaced apart from each other (see FIG. 6A). If the powder dispensingmouth 54 of the cartridge unit 5′ is moved toward the material storageframe 24′, the lid levers 56 come into contact with the bars 27 and makesliding movement along the side surface of the roller-shaped housing 50.At this time, the lid plates 55 are slid together with the lid levers 56to open the powder dispensing mouth 54. Thus the powdery material Mcharged in the cartridge unit 5′ falls down on the material storageframe 24′ (see FIG. 6B). As the cartridge unit 5′ is inserted into thematerial storage frame 24′, the aperture area of the powder dispensingmouth 54 becomes greater, thereby increasing the quantity of the powderymaterial M fed from the cartridge unit 5′. By making the powderdispensing mouth 54 of the cartridge unit 5′ openable and closable asset forth above, it is possible to adjust the feeding quantity of thepowdery material M in a timely manner.

Alternatively, the cartridge unit 5′ of the present embodiment may beconfigured so that the powder dispensing mouth 54 can be opened insynchronism with the movement of the powder layer forming unit 2. Withthis configuration, the powder dispensing mouth 54 can be opened onlywhen there is a need to feed the powdery material M. This makes itpossible to feed the powdery material M in a proper quantity and tosuppress degradation of the powdery material M.

As a modified example of the present embodiment, the cartridge unit 5′may include a screw 57 contained therein as shown in FIG. 7. The screw57 is driven by a motor 58. Since the screw 57 is rotated within thecartridge unit 5′ to stir the powdery material M, it is possible toprevent the cartridge unit 5′ from clogging with the powdery material Mand to smoothly feed the powdery material M. Even when the powderdispensing mouth 54 of the cartridge unit 5′ is closed, it is possibleto stir the powdery material M charged in the cartridge unit 5′. Thismakes it possible to keep uniform the particle size and homogeneity ofpowdery material components.

Preferably, the cartridge unit 5′ further includes a drying unit fordrying the powdery material M charged therein. The drying unit may be,e.g., an electrothermal wire 59 arranged in the screw 57. Alternatively,it may be possible to arrange a heat transferring heater in the sidewall of the cartridge unit 5′. This makes it possible to prevent thepowdery material M charged in the cartridge unit 5 from absorbingmoisture. The apparatus 1 may further include a vibration unit forvibrating the cartridge unit 5′. As the vibration unit, it may bepossible to use, e.g., the mobility of the cutting unit 6 or the powerof the motor 58 for driving the screw 57. By doing so, the powderymaterial M can be completely used up with no waste and with nopossibility that the powdery material M stays behind within thecartridge unit 5′. It is preferred that the vibration unit is applied tothe disposable cartridge unit 5 set forth above.

The present invention shall not be limited to the configurations of theforegoing embodiments but may be modified in many different forms.Although the cartridge unit 5 is preliminarily installed above the baseframe 41 in the foregoing embodiments, the apparatus 1 may be providedwith a cartridge accommodation portion for accommodating a plurality ofcartridge units 5. More preferably, the apparatus 1 may be configured sothat the transportation unit can automatically replace the cartridgeunit 5 with a new one if the quantity of the powdery material M storedin the material storage frame 24 is reduced.

Although the foregoing embodiments are described with respect to theexample that the powdery material M is fed into the material storageframe 24 and is leveled by sliding the material storage frame 24, thepresent invention is not limited to this example. For example, as shownin FIG. 8, it may be possible to use as the slide member 20 only ablade-shaped member 200 or the slide frame 23, either of which has awidth greater than that of the base 40 so that it can level the surfaceof the powdery material M fed on the upper surface of the base 40. Inthis case, the powdery material M may be directly fed from the cartridgeunit 5 to a specified position on the upper surface of the base frame 41that surrounds the base 40 and then may be leveled by sliding theblade-shape member 200. Alternatively, the powdery material M may bedirectly fed from the cartridge unit 5 onto the base 40 (or the powderlayer or solidified layer formed on the base 40). As a furtheralternative example, the material storage frame 24 alone may be used asthe slide member 20.

While the invention has been shown and described with respect to thepreferred embodiments, it will be understood by those skilled in the artthat various changes and modification may be made without departing fromthe scope of the invention as defined in the following claims.

What is claimed is:
 1. An apparatus for producing a laminated object,comprising: a powder layer forming unit configured to form a powderlayer of a powdery material; a material supply unit configured to feedthe powdery material to the powder layer forming unit; and a solidifiedlayer forming unit configured to form a solidified layer by irradiatinga light beam on a specified portion of the powder layer and sinter ormelt the specified portion of the powder layer on a base and a baseframe surrounding the outer circumference of the base, the apparatusbeing configured to produce an integrally laminated three-dimensionalobject by repeating formation of the powder layer and formation of thesolidified layer, wherein the material supply unit comprises a cartridgeunit charged with the powdery material, the cartridge unit beingconfigured to allow the powdery material to drop downwards, wherein thepowder layer forming unit includes a slide member which comprises aslide frame and a material storage frame, the material supply unit beingconfigured to feed the powdery material charged in the cartridge unit tothe material storage frame, and the slide member is arranged for slidingmovement along an upper surface of the base frame, where the lowersurface of the slide member makes contact with the upper surface of thebase frame and the slide member moves along to bring the powderymaterial onto the base, where the slide member includes the slide framewhich has a lower surface opening that has a greater surface area thanan upper surface of the base; wherein the cartridge unit has a drumshape and has a powder dispensing mouth through which to feed thepowdery material provided in a bottom portion thereof, the bottomportion being a sidewall of the cartridge unit and wherein the cartridgeunit is provided with a lid plate configured to slide along the sidewallthereof to thereby, open and close the powder dispensing mouth.
 2. Theapparatus of claim 1, further comprising a transportation unitconfigured to clamp and transport the cartridge unit.
 3. The apparatusof claim 1, wherein the material storage frame is configured to allowthe cartridge unit to be partially or fully inserted thereinto.
 4. Theapparatus of claim 1, wherein the material supply unit is configured tofeed the powdery material charged in the cartridge unit onto a base onwhich the powder layer and/or the solidified layer is formed or a baseframe surrounding the base.
 5. The apparatus of claim 1, wherein thepowdery material charged in the cartridge unit is dropped by opening thebottom portion.
 6. The apparatus of claim 1, wherein the cartridge unitis configured to allow the powder dispensing mouth to be opened when thecartridge unit is inserted into a material storage frame.
 7. Theapparatus of claim 6, wherein the cartridge unit is configured to allowthe powder dispensing mouth to be opened in synchronism with movement ofthe powder layer forming unit.
 8. The apparatus of claim 1, wherein thecartridge unit has a screw installed therein.
 9. The apparatus of claim1, further comprising a drying unit for drying the powdery materialcharged in the cartridge unit.
 10. The apparatus of claim 1, wherein thecartridge unit has an internal space charged with the powdery materialand kept hermetically sealed.
 11. The apparatus of claim 1, wherein thecartridge unit is made of a reusable plastic material or a papermaterial with sealability.
 12. The apparatus of claim 1, wherein the lidplate is provided with a lid lever extending in the longitudinaldirection of the drum-shaped cartridge unit, and the powder dispensingmouth is opened and closed by the lid lever.